2 Tier ADCS PKI what's different when using HSM's?

In the near future I will be tasked with building a Tier 2 ADCS PKI that uses HSM's, can anyone tell me what I have to do differently when building the PKI, and how the HSM fits into the whole PKI? (Win 2016 or Win 2019 Server) I have a lot of experience with building tier 2 ADCS PKI's but I've never worked with HSM's before.